Practical Analysis of Permeable Concrete Properties with Polypropylene Fiber Addition

This paper focuses on comparing the behavior of RC tension members with and without the addition of polypropylene fibers at various corrosion levels. Eight cylindrical tensile specimens were tested to evaluate their tension-stiffening and cracking behavior. The content of polypropylene fiber added into the concrete mix was the main variable (0.25%, 0.50%, 0.75%, and 1.0% of total volume). The corrosion level was varied from slight (5%), medium (10%) to severe (30%) and, like the other variables, applied only to 1.0% polypropylene fiber-reinforced concrete (PFRC) specimens. The test results showed that the fiber addition significantly increased the tension-stiffening effect but was largely unable to reduce the effect of bond degradation caused by corrosion. Moreover, the addition of polypropylene fibers was able to improve the cracking behavior in terms of crack propagation, as shown by smaller crack spacing compared to the specimen without fiber addition at the same corrosion level.

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Effect of different fiber types on the mechanical properties of normal and high strength concrete at elevated temperatures

Challenge Journal of Concrete Research Letters ◽

10.20528/cjcrl.2021.01.004 ◽

2021 ◽

Vol 12 (1) ◽

pp. 30

Author(s):

Mohamed Amin ◽

Khaled Abu el-hassan

Keyword(s):

Mechanical Properties ◽

High Temperature ◽

High Strength Concrete ◽

Elevated Temperatures ◽

Polypropylene Fiber ◽

High Strength ◽

Fiber Types ◽

Strength Concrete ◽

Compressive And Flexural Strengths ◽

Fiber Addition

The effects of the types of fibers on mechanical properties of normal and high strength concrete under high temperature, up to 700 °C, was investigated. Three different- type fiber; "Steel Fiber (SF), Glass Fiber (GF) and Polypropylene Fiber (PPF)" are added into the concretes in five different ratios (0, 0.50, 1.00, 1.50 and 2.0%)of the volume under the following temperatures; 22, 100, 400 and 700°C. The results indicate that all the different types of fibers researched contribute to both the compressive and flexural strengths of concrete under high temperature, however, it is also found that this contribution decreases with an increase in temperature. The flexural strengths and compressive strengths for NSC and HSC mixes at 28 days under high temperature decreases as the temperature increases especially up to 400°C. Also, the best compressive and flexural strengths performance under high temperature was also those of SF. The compressive strength of the concrete incorporating SF was reduced under high temperature only, while the mixes containing PPF and GF were reduced under high temperature or with fiber addition. The optimum fiber addition ratios of the mixes containing PPF and GF are between 0.5-1.0 percent by volume. And for SF, it is 1.5% by the volume.

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Use of polypropylene fiber and silica fume modified concrete as a repair material

MATEC Web of Conferences ◽

10.1051/matecconf/201819907008 ◽

2018 ◽

Vol 199 ◽

pp. 07008

Author(s):

Jing Liu ◽

Wen Liu ◽

Shugang Guan ◽

Chao Guo ◽

and Xinguo Zheng

Keyword(s):

Compressive Strength ◽

Silica Fume ◽

Cement Paste ◽

Polypropylene Fiber ◽

Repair Material ◽

Chloride Permeability ◽

Cracking Resistance ◽

Transition Zones ◽

Concrete Properties ◽

Fiber Matrix

Polypropylene fiber and silica fume were used to get high impermeability and cracking resistance concrete as a repair material. Results showed just incorporating fiber (without silica fume) had no obvious improvement on strength and impermeability of concrete. The usage of polypropylene fiber and silica fume together in concrete increased the compressive strength and caused a significant reduction in chloride permeability. The improvement of fiber and silica fume on concrete properties was attributed to both the anti-cracking effect from polypropylene fiber and densification reinforcement action to the interfacial transition zones of both fiber —matrix and aggregate—cement paste from silica fume. These properties made them suitable for certain applications such as concrete repairs.

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Power Projects and Covid-19: A Practical Analysis of the Relevance of Force Majeure Clauses under the Standardised Power Purchase and Implementation Agreements of Uganda

Global Energy Law and Sustainability ◽

10.3366/gels.2020.0026 ◽

2020 ◽

Vol 1 (2) ◽

pp. 189-193

Author(s):

Aisha Naiga ◽

Loyola Rwabose Karobwa

Keyword(s):

Renewable Energy ◽

Renewable Energy Sources ◽

Clean Energy ◽

The State ◽

Energy Sources ◽

Policy Goals ◽

Force Majeure ◽

Practical Analysis ◽

Energy Justice

Over 90% of Uganda's power is generated from renewable sources. Standardised Implementation Agreements and Power Purchase Agreements create a long-term relationship between Generating Companies and the state-owned off-taker guaranteed by Government. The COVID-19 pandemic and measures to curb the spread of the virus have triggered the scrutiny and application of force majeure (FM) clauses in these agreements. This article reviews the FM clauses and considers their relevance. The authors submit that FM clauses are a useful commercial tool for achieving energy justice by ensuring the continuity of the project, despite the dire effects of the pandemic. Proposals are made for practical considerations for a post-COVID-19 future which provides the continued pursuit of policy goals of promoting renewable energy sources and increasing access to clean energy, thus accelerating just energy transitions.

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Research on uniaxial compression constitutive model of polypropylene fiber recycled brick concrete

Revista de la Facultad de Ingeniería ◽

10.21311/002.31.4.11 ◽

2016 ◽

Vol 31 (4) ◽

Keyword(s):

Constitutive Model ◽

Uniaxial Compression ◽

Polypropylene Fiber

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